Authorities have yet to uncover a motive behind a bombing in Manhattan's Chelsea neighborhood which left 29 people injured late Saturday, New York City Mayor Bill de Blasio said during a press conference held Sunday in conjunction with local law enforcement. Blasio stressed the investigation into Saturday's explosion was ongoing and emphasized his desire to avoid speculation by sharing only confirmed information.

"We're going to be very careful and patient to get to the full truth here," Blasio said. "We're not going to jump to conclusion. We're not going to offer you easy answers. We're going to make sure we have all the facts. We know there was a bombing, that much we do know. We know there was a very serious incident. But we have a lot more work to do before we can say what motive was behind this. Was it a political motivation? Was it a personal motivation? We don't know that yet."

Before handing things over to law enforcement officials the mayor confirmed that all 29 people injured in the blast on 23rd Street have since been released from the hospital. The New York Police Department is working with the Federal Bureau of Investigation, the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Joint Terrorism Task Force to investigate two explosive devices found Saturday roughly four blocks apart.

Components characteristic of an IED, or improvised explosive device, were found at the 23rd Street crime scene, New York City Police Commissioner James O'Neill said. In a sweep of the surrounding area following the blast on 23rd Street, a possible second device, made from a pressure cooker, was found on 27th Street in a bag. That device has been taken to Quantico, the FBI's training facility, for further analysis. Although authorities have yet to establish evidence of a concrete link between the two devices, they are operating under the assumption the two are connected, Chief of Detectives Robert Boyce said Sunday.

Officials also said they currently had "no specific evidence" linking Saturday evening's bombing in Chelsea to a pipe bomb that went off earlier in the day before a Marine Corps charity run in Seaside Park, New Jersey, but would continue to investigate a possible connection between the two incidents. "We're not taking any options off the table," Blasio said.

Blasio applauded New Yorkers' resiliency and refusal to be intimidated but urged them to be vigilant and warned of an increased police presence throughout the coming week. "We're going into United Nations general assembly week," he said. "You will see a very substantial NYPD presence this week. We would normally have an expanded presence for the United Nations general assembly, it will be even bigger."